Byron is alleged to have invited workers to a fake ‘training day’ on 4 July where they were met by figures from the Home Office.
The claims were originally made in the Spanish language newspaper El Iberico leading to a backlash on social media with the #boycottbyron tag.
The Home Office confirmed that 35 people from Albania, Brazil, Nepal and Egypt were arrested and that the raids had been carried out with Byron’s ‘full co-operation’.
Byron had conducted the correct ‘right to work’ checks on staff, but had been shown fake papers, it said.
As a result, the firm will not face any penalty action.
A Byron spokesperson said: “We can confirm that several of Byron's London restaurants were visited by representatives of the Home Office.
"These visits resulted in the removal of members of staff who are suspected by the Home Office of not having the right to work in the UK, and of possessing fraudulent personal and right to work documentation that is in breach of immigration and employment regulation.”
The firm added that it was ‘proud of the diversity’ of its restaurant teams, which were ‘built around people of all backgrounds and all walks of life’.
But yesterday Twitter users began calling for a boycott of the chain using the #boycottbyron tag, with some criticising the chain as ‘morally repugnant’.
A protest organised by groups including the Unite union's Hotel Workers branch has been organised for Byron’s High Holborn store on 1 August, with over 500 people apparently planning to attend.
However, others insisted the company was right to act within the law.